When a white person kills a black man in America, the killer often faces no legal consequences. In one in six of these killings, there is no criminal sanction, according to a new Marshall Project examination of 400,000 homicides committed by civilians between 1980 and 2014. That rate is far higher than the one for homicides involving other combinations of races.

From 1980 to 2014, roughly three percent of all homicides in America were ruled justified. But a striking disparity persists in killings involving a white person and a black male victim. In these instances, write Anna Flagg and Daniel Lathrop in a recent analysis published by The Marshall Project and The New York Times’s Upshot, killings were ruled justifiable more than eight times as often as others.

We caught up with Flagg, an interactive reporter at The Marshall Project, to talk about the methodology behind the analysis and explore its possible impact on the criminal justice system in America.

The following interview has been edited for length and clarity. It has been crossposted on Northeastern School of Journalism’s site The Docket, too.

You have degrees in math and human/computer interaction. Have you always intended on working in journalism?